The present invention relates to a plasma display panel (hereafter may also be referred to as PDP), and a plasma display apparatus including a drive apparatus.
In recent years, as a large-size and thin-type color display apparatus, practical application of an alternating current (AC) surface discharge-type PDP has been progressing. Explanation will be given below on embodiments of the AC surface discharge-type PDP which is conventional technology.
FIG. 2 is an example of a disassembled perspective view showing a part of a structure of a general AC surface discharge-type PDP. A PDP 38 shown in FIG. 2 is one configured by a front plate 36 composed of a glass front substrate 21 or the like, and a rear plate 37 composed of a rear substrate 28 or the like, which are adhered to make one piece.
The front substrate 21 has a plurality of sustained discharge electrode pairs formed in parallel with a constant distance apart. This sustained discharge electrode pair is configured by an X electrode 22 (hereafter may also be referred to as X), which is a first electrode, and a Y electrode 23 (hereafter may also be referred to as Y), which is a second electrode. The X electrode 22 is configured by an X transparent electrode 22a and an X bus electrode 22b, which aims at compensation of electric conductivity of the transparent electrode. In addition, the Y electrode 23, similarly, is configured by a Y transparent electrode 23a and a Y bus electrode 23b. The X bus electrode 22b and the Y bus electrode 23b are provided extending in a direction of the arrow mark D2 (line direction) in FIG. 2. The X electrode 22 and the Y electrode 23 are covered with a dielectric layer 26, and this dielectric layer 26 is covered with a protective film 27.
In FIG. 2, a plurality of the sustained discharge electrode pairs are arranged to form X-Y-Y-X-X-Y-Y-X-X--- in a direction of the arrow mark D1. Such an arrangement is called an XYYX arrangement. On the other hand, it may be arranged to form X-Y-X-Y-X-Y-X-Y---. Such an arrangement is called an XYXY arrangement. By taking the XYYX arrangement, inter-electrode capacity between each of the adjacent X electrodes themselves and the Y electrodes themselves can be eliminated, by which generation of ineffective power can be suppressed, as compared with the XYXY arrangement.
The rear substrate 28 has an address electrode 29 (hereafter referred to simply as an A electrode) which intersects at right angles with the X bus electrode 22b and the Y bus electrode 23b of the front substrate 21, and this A electrode 29 is covered with a dielectric material 30. This A electrode 29 is provided extending in a direction of the arrow mark D1 (row direction) in FIG. 2. On the dielectric material 30, a rib 31 is provided to prevent spread of discharge (to specify discharge region). On the dielectric material 30, a discharge cell DC is provided, which is partitioned by this rib 31. On the discharge cell DC, each of fluorescent material layers 32R, 32G and 32B are coated, which emit red, green and blue light, respectively.
FIG. 3 is a cross-sectional view of an important part of a PDP shown in FIG. 2, viewed from a direction of the arrow mark D2. Reference numeral 33 shows a discharge space filled with discharge gas for generation of plasma. When voltage is applied between electrodes, plasma 10 is generated by ionization of the discharge gas. FIG. 3 shows schematically a generated state of the plasma 10. Ultraviolet rays from this plasma make the fluorescent material layer 32 excited for emission, and the emission from the fluorescent material layer 32 transmits the front substrate 21, and a display view screen is configured by emission from each of the discharge cells.
FIGS. 4A-4C are drawings showing operations in one TV field period required to display one image on the PDP shown in FIG. 2. FIG. 4A is a time chart. As shown in (I), the one TV field period 40 is divided into subfields 41 to 48 having a plurality of different emission frequency. Selection of emission and non-emission by each of the subfields expresses color tone. Each of the subfields is configured by a reset period 49, an address discharge period 50 specifying an emission cell, and a sustained discharge period 51, as shown in (II).
FIG. 4B shows a voltage waveform applied to the A electrode, X electrode and Y electrode, in the address discharge period 50 of FIG. 4A. The waveform 52 shows voltage waveform applied to one A electrode in the address discharge period 50, waveform 53 shows voltage waveform applied to the X electrode, and waveforms 54 and 55 show voltage waveforms applied to the i-th and (i+1)-th Y electrodes, and voltages are designated as Vo, Vi and V2 (V), respectively. In FIG. 4B, width of address voltage pulse applied to the A electrode is shown as ta. According to FIG. 4B, when a scanning pulse 56 is applied to the i-th line of Y electrode, address discharge is generated at a cell positioned at an intersection with the A electrode. In addition, even when the scanning pulse 56 is applied to the No. i line of Y electrode, address discharge is not generated in the case where the A electrode is at the ground potential (GND). In this way, in the address discharge period 50, scanning pulse is applied to the Y electrode once, and at the A electrode, in response to the scanning pulse, an emission cell has V0, and a non-emission cell is at the ground potential. At this discharge cell generated this address discharge, charges generated by discharge are formed on the surface of the dielectric layer covering the A electrode and the protective film. By support of this electric field generated by the charges, ON-OFF of sustained discharge, to be described later, can be controlled. That is, a discharge cell generating address discharge becomes an emission cell, and others become non-emission cells.
FIG. 4C shows voltage pulse applied all at the same time between the X electrode and the Y electrode, which is the sustained discharge electrodes, during the sustained discharge period 51 of FIG. 4A. Voltage waveform 58 is applied to the X electrode, and voltage waveform 59 is applied to the Y electrode. In both cases, by alternating application of pulse with the same polarity and with voltage V3 (V), relative voltage between the X electrode and the Y electrode repeats the inversion. Discharge generated in this period in discharge gas between the X electrode and the Y electrode is called sustained discharge.
It should be noted that in trying to achieve a low power consumption, highly precise and high quality PDP, having brightness and long life assured and enabling stable drive, there is a problem of address discharge characteristics, in particular, address discharge delay. Detail of the address discharge delay will be described later.
Large address discharge delay results in failure in address discharge and makes subsequent sustained discharge impossible, which generates a view screen flicker. Furthermore, drive of a PDP over a prolonged period of time raises also a problem of an increase in address discharge delay (deterioration over time). That is, lighting of a PDP over a prolonged period of time also results in generation of a view screen flicker.
As a method for solving this problem, as shown in JP-A-2002-297091, there has been proposed a PDP with reduced discharge delay, with an electrode arrangement of XYYX-type, and by providing an auxiliary electrode adjacent to the Y electrode, in parallel, on a front plate, and by generation of priming discharge by an in-plane auxiliary electrode at the front plate side. In addition, as shown in JP-A-2003-217458, there has been proposed a PDP with electrode arrangement of XYYX-type for achieving enhancement of emission efficiency in the first discharge region and enhancement of address discharge characteristics in the second region at the same time, and by providing the first discharge region for executing sustained discharge, the second discharge region for executing address discharge, and a gap part connecting both discharge regions, and by execution of address discharge between the Y bus electrode and the address electrode, in the second discharge region partitioned by “rib extending in a row direction and in a line direction”.